The advent of indoor plumbing and flush toilets, and decades of use and gradual improvement started with simple plug and flapper tank valves that were levered open, to remain open while a full tank emptied, and a ballcock valve which was open whenever the water level in the tank was below a storage level. While the ballcock valve was open, part of its total flow was diverted to refill the bowl at the same time the tank was being refilled. That procedure remains the same to this day for systems which use stored water to flush the toilet.
Nearly every year there has been an improvement in some part of the conventional systems. Tank-valves have evolved into many forms of pivoted plates and floats. Ballcock valves have evolved from simple floats on a lever that pressed on a valve plate, to differential pressure actuated valves that require movement by the float of only a pin to open or close a very small bleed orifice for their control.
The floats themselves have evolved from copper spheres to foam bodies, to inverted cups of various shapes. Some were on lever arms. Others embraced an upright post. The ultimate limit on the water level was overflow into the bowl, through the same passage as was provided for the bowl refill.
The industry was greatly assisted by the development of plastic materials of construction. These materials need to resist pressure-for a long time and also resist chemicals which would show up in the water from time to time. They enable the production of shapes and parts which could not economically be produced by metal casting and machinery processes.
As a disadvantage these new shapes and materials also enabled the production of sophisticated products in low-cost countries, to the disadvantage of domestic production. As a consequence, there has been significant incentive to invent and market even more sophisticated products hopefully made as inexpensively and perhaps better in the United States.
If it were merely a matter of making a same thing cheaper, there would be no merit in making changes. However, as the availability of these products (in part because of their low cost) improved, and along with population growth, the effluent from their systems also has increased to the extent that sewage systems designed for lesser loads are being overwhelmed.
The response to this problem has been to redefine how much water a toilet is permitted to discharge per flush. Low volume flush systems are now routinely required. Whereas in the past a large flush which depended on a sustained and relatively slow flow of water was the norm, now a much lesser amount of water is permitted for each flush cycle to do the same job. In order for this to happen a quick, high rate of flow of a low total volume of water is needed to wash away the waste.
Systems using direct flow from a pressure valve can often attend to this, but systems favored in less commercial places such as residences tend to use water tanks. It is an object of this invention to provide a water tank system with the capability of a sufficient and very rapid discharge of stored water.
As it happens, such improved systems involve related problems of their own. While each problem is relatively small, together they add up to a significant challenge. For example, to discharge a large volume quickly requires a large area discharge port and an equally large closure for it. The force required to lift the closure off of the discharge port valve seat is proportionally increased to the extent that it is difficult for an average person to operate.
Here, the ultimate problem is in the inefficiency of the trip lever used to lift the valve. The lever is inherently inefficient because the outside handle or knob available to the user is short, and the inside lever it turns is long. In itself it magnifies the force necessary to turn the handle, thereby compounding the problem.
It is an object of this invention to reduce the force needed to open the tank valve. In fact, without the improvements of this invention it may take as much as 10 pounds force on a 3 inch handle to open the valve. With the improvements of this invention, the required force to open a 3 inch diameter plug valve is only about 3 pounds. 10 pounds is too much force for many people, while 3 pounds is tolerable by almost everybody.
Another problem arises from the-variations of dimensions of installed systems. To compensate for these, trip levers have often lifted a valve closure with flexible links such as chains or cables. This invention provides a lifting lever with a profile suitable for a wide range of dimensions for actuating the valve closure, and which does not require a flexible link. This is a savings in cost and, as will be seen, is also an improvement in function.
Conventional tank valves often rely on a pivoted valve closure which is costly and subject to later malfunction. It is an object of this invention to provide a single piece valve closure of surprisingly simple design—a unibody with a distinctive exterior, a passage entirely through the closure, with a lower guide and an upper end receptive of refill water, and which when open is a freely floating body without restraint to the tank structure. It can readily be opened by a tilting, rather than an axial movement, requiring less physical force to open the valve.